1. Field of the Invention
The present invention is directed to novel cyclopropane compounds and, more specifically, to 2-vinyl- and 2-ethylcyclopropane compounds having a carboxylate moiety and a nitrile or aryl group substituted at the 1-position on the ring. The compounds of this invention are useful as chemical intermediates, pesticides and insecticides.
2. Discussion of the Prior Art
Pyrethrin and various synthetic compounds modeled thereafter, such as allethrin, are well known and while primarily recognized for their insecticidal properties are also useful for a variety of other applications. In view of the diverse physical and chemical properties possible with such products, much effort has been directed to the synthesis of other structurally related compounds, i.e., based on the cyclopropane structure.
The number of cyclopropane monocarboxylate compounds reported having only two of the ring positions substituted is limited and compounds of this type wherein a nitrile or aryl group is present at the same ring position as the carboxylate group are even more limited. Kierstead et al. (J. Chem. Soc., 1953, 1799-1803) reported the preparation of ethyl 1-cyano-2-vinylcyclopropane-1-carboxylate by the condensation of ethyl sodiocyanoacetate with 1,4-dibromobutene-2. The ability to obtain other related compounds was restricted, however, due to the limitations of the condensation reaction.
In U.S. Pat. No. 4,220,591 insecticidal cyclopropane esters are prepared via a carbene insertion reaction with a phenyl acrylic acid. The products conform to the formula ##STR1## wherein R.sub.1 is hydrogen or a methoxy, ethoxy, propoxy, methylthio, ethylthio, propylthio, fluoro, chloro, bromo, methyl, ethyl, nitro or amino group, and R.sub.2 is a hydrogen or methyl group or R.sub.1 and R.sub.2 together form a methylenedioxy group; R.sub.3 is hydrogen, or a lower alkyl group, or one of the following groups (a) to (d):
(a) m-phenoxybenzyl PA1 (b) 2-benzyl-4-furylmethyl PA1 (c) .alpha.-cyano-m-phenoxybenzyl PA1 (c) 3,4-methylenedioxy-benzyl, and
R.sub.4 and R.sub.5 are the same or different groups and each is a fluoro, bromo, chloro or methyl group.